J105 Owner Manual 2012.pdf - J/Owners

J/105 Owner Guide ...................................................................................................................................................................................................................................................... 2 

J/105 Owner Manual 

HIN:……………………………………. 

Yacht Name:…………………………………… 

Owner Name:…………………………………… 

COPYRIGHT © J/BOATS, INC., 2012


Table of Contents 

Introduction ...................................................................................................................................................................... 4 

Specifications .................................................................................................................................................................... 6 

Important Contacts ........................................................................................................................................................ 7 

Getting Started ................................................................................................................................................................. 8 

Commissioning Checklist ......................................................................................................................................... 13 

Tuning The Rig .............................................................................................................................................................. 14 

IMPORTANT Commissioning Follow-‐up ........................................................................................................... 15 

Diagrams, Layouts, & Schematics .............................................................................................................. 16 

Running Rigging & Deck Hardware Layout ........................................................................................... 16 

Mainsheet & Cunningham Diagram .......................................................................................................... 17 

Steering System ................................................................................................................................................. 18 

Fuel & Exhaust System ................................................................................................................................... 19 

Thru-‐Hull & Seacock Locations ................................................................................................................... 20 

Manual Fresh Water System ........................................................................................................................ 21 

Head & Holding Tank Schematic ................................................................................................................ 22 

12 V DC Wiring System ................................................................................................................................... 23 

Battery Wiring System .................................................................................................................................... 24 

Lightning/Bonding System ........................................................................................................................... 25 

Engine System ............................................................................................................................................................... 26 

Drive Train ...................................................................................................................................................................... 26 

Fuel System .................................................................................................................................................................... 27 

Cooling System .............................................................................................................................................................. 28 

Exhaust System ............................................................................................................................................................. 28 

General Hints to Avoid Problems ......................................................................................................................... 28 

Engine Safety Precautions ....................................................................................................................................... 29 

Bleeding the Engine .................................................................................................................................................... 30 

Starting Up the Engine ............................................................................................................................................... 30 

Shutting Down the Engine ....................................................................................................................................... 31 

Fueling .............................................................................................................................................................................. 31 

Engine Maintenance ................................................................................................................................................... 32 

Plumbing Systems ....................................................................................................................................................... 33 

Manual Fresh Water ................................................................................................................................................... 33 

Thru-‐Hulls & Seacocks .............................................................................................................................................. 33 

Pump Systems ............................................................................................................................................................... 33 

Head System .................................................................................................................................................................. 34 

Electrical System .......................................................................................................................................................... 36 

Safety ................................................................................................................................................................................. 37 

Lightning Protection ................................................................................................................................................... 38 

Galley Stove .................................................................................................................................................................... 39 

Maintenance Tips ........................................................................................................................................................ 39 

Annual Maintenance Checklist ............................................................................................................................... 43 

Storage Tips ................................................................................................................................................................... 44 

APPENDIX A -‐ Best Practices -‐ Boat Inspection .............................................................................................. 46 

APPENDIX B -‐ ABS (Dated) Guidelines for Survey After Construction ................................................ 51 

APPENDIX C -‐ US Watercraft Warranty ............................................................................................................. 52


Introduction 

WELCOME ABOARD and welcome to the J/Boats family of owners. Your boat is designed and 

engineered to be the strongest, best performing, easiest-‐to-‐use, and most comfortable sailing 

boat of its type. 

Sailing involves risk, most of which can be minimized with advance planning and proper 

seamanship. The J/105 owner should become proficient in all aspects of handling the vessel 

under sail and power, and be well versed with emergency procedures before undertaking any 

offshore passage. The owner is further responsible for any required state registration or federal 

documentation, accident reporting, outfitting the vessel with proper safety equipment, and the 

safe operation of the vessel. Your J/Boats Dealer will be happy to refer you to Boating Safety 

Courses or other seminars available. 

This owner manual is furnished for your benefit, but shall in no way be construed as any sort of 

warranty or contract, express or implied, creating any obligation on the part of J/Boats, Inc., with 

respect to any fact or facts or any advice or opinions contained herein. The sole and exclusive 

warranty of the product is the US Watercraft Warranty described in the appendix hereto and on 

the Warranty Card furnished with the yacht. 

J/BOATS, INC. HEREBY DISCLAIMS ANY AND ALL WARRANTIES, EXPRESS OR IMPLIED, 

INCLUDING ANY WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE OR ANY IMPLIED 

WARRANTY OF MERCHANTABILITY. 

Please be sure to complete the warranty card provided with the boat and mail to US Watercraft.


This manual has been compiled to help you to operate your J/105 with safety and pleasure. It 

contains details of the J/105 the equipment supplied or fitted, its systems and information on its 

operation. Please read it carefully, and familiarize yourself with the craft before using it. 

This owner's manual is not a course on boating safety or seamanship. If this is your first boat, or 

you are changing to a type of boat you are not familiar with, for your own comfort and safety, 

please ensure that you obtain handling and operating experience before "assuming command" of 

the boat. Your dealer or national sailing federation or yacht club will be pleased to advise you of 

local sea schools, or competent instructors. 

This owner's manual is not a detailed maintenance or trouble shooting guide. In case of difficulty, 

refer to the boat dealer, builder or its representative. Always use trained and competent people 

for maintenance, fixing or modifications. Modifications that may affect the safety characteristics 

of the craft shall be assessed, executed and documented by competent people. The boat builder 

cannot be held responsible for modifications he has not approved. 

NOTE: Any change in the disposition of the masses aboard may significantly affect the stability, 

trim and performance of your boat. Users of this boat are advised that: 

• All crew should receive suitable training; 

• Bilge water should be kept to a minimum; 

• Stability is reduced by any weight added high up; 

• In rough weather, hatches, lockers and doorways should be closed to minimize the risk of 

flooding; 

• Stability may be reduced when towing or lifting heavy weights using a davit or boom; 

• Breaking waves are serious stability hazard. 

• In some countries a driving license or authorization are required, or specific regulations 

are in force. 

• Always maintain your boat properly and make allowance for the deterioration that will 

occur in time and as a result of heavy use or misuse of the boat. 

• Any boat – no matter how strong it may be, can be severely damaged if not used properly. 

This is not compatible with safe boating. Always adjust the speed and direction of the 

craft to sea conditions. 

• If your boat is fitted with a life raft, read carefully its operating manual. The crew should 

be familiar with the use of all safety equipment (harness, flares, life raft, etc.) and 

emergency maneuvering (man overboard recovery, towing, etc); sailing schools and clubs 

regularly organize drill sessions. 

PLEASE KEEP THIS MANUAL IN A SECURE PLACE, AND HAND IT OVER TO THE NEW OWNER WHEN YOU 

SELL THE CRAFT.


Specifications 

MODEL .......................................................................................................................................................... J/105 

LOA ................................................................................................................................................ 10.51m (34.50') 

LWL ................................................................................................................................................. 8.99m (29.50') 

Beam ............................................................................................................................................... 3.35m (11.00') 

Draft ................................................................................................................................................... 1.98m (6.50') 

Ballast (Lead)........................................................................................................................ 1,542 kg (3,400 lbs.) 

Class Minimum Weight (see class rules) ............................................................................... 3,890 kg (8,576 lbs.) 

100% Sail Area .................................................................................................................... 53.60 sq m (577 sq ft) 

IM ................................................................................................................................................... 12.37m (40.60') 

ISP ................................................................................................................................................. 12.83m (42.1’’) 

J ...................................................................................................................................................... 4.11m (13.50') 

P .................................................................................................................................................... 12.65m (41.50') 

E ...................................................................................................................................................... 4.45m (14.60') 

Engine ................................................................................................................... Yanmar 3YM20, 15.3kw (21hp) 

Fuel Capacity* ............................................................................................................... 45.4 liters (12 US gallons) 

Engine Alternator ............................................................................... 60 amp standard Yanmar marine alternator 

House Battery Capacity ................................................................................... 90 amp hours, add’l 90 amp option 

Standard Propeller ..................................................................................... Martec folding prop 15” dia. x 14” pitch 

Battery Type ......................................................................................................................................... Deep-cycle 

Holding Tank Capacity ................................................................................................................. 45 liters (12 gal.) 

Water Capacity** ......................................................................................... 18.9 liter (5 US gallon) Portable Tank 

Hull & Deck Core Material ...................................................................................................... Baltek® SB50 Balsa 

Hull & Deck Molding Process ............................................................................................................. Hand Lay-up 

Hull Blister Warranty ................................................................................................. 10 Year: Owner Transferable 

Mast Height Above Water .................................................... 15.34 m (50’ 4”) not including masthead instruments 

* Fuel capacity may not be completely usable depending upon trim and loading of the craft and a 

20% reserve should be kept on board. 

** All water capacity may not be usable depending upon trim and loading of the craft.


Important Contacts 

Dealer: .................................................................................... Phone: ................................................................................ 

Street: ...................................................................................... Web Site: ........................................................................... 

City, State, Zip: ..................................................................... E mail: ................................................................................. 

Marketing & Design J/Boats, Inc. 401-‐846-‐8410 

PO Box 90 

info@jboats.com 

Newport, RI 02840 

Builder: US Watercraft 401-‐682-‐1661 

225 Alexander Rd. info@waterlinesystems.com 

Portsmouth, RI 02871 

Cushions: Ken’s Upholstery 401-‐246-‐1244 

101 Narragansett Ave. 

Barrington, RI 02806 

Canvas: Thurston Sails 401-‐254-‐0970 

Tupelo Street 

thurstoncanvas@fullchannel.net 

Bristol, RI 02809 

Spars: Charleston Spar, Inc. 704-‐597-‐1502 

3901 Pine Grove Circle sales@sparcraft-‐us.com 

Charlotte, NC 28206 

Hydraulics: Sailtec, Inc. 920-‐233-‐4242 

2930 Conger Court info@sailtec.com 

Oshkosh, WI 54904 

Deck Hardware: Harken 262-‐691-‐3320 

1251 E. Wisconsin Ave. harken@harken.com 

Pewaukee, WI 53072 

Deck Hardware: Spinlock USA 877-‐465-‐6251 

PO Box 2672 

www.SpinlockUSA.com 

Newport, RI 02840


Getting Started With Your J/105 

Generally, your dealer or commissioning yard will help you prepare your boat before launching. 

And in most instances they will undertake the entire commissioning job. They are experts in the 

field and are capable of completing most commissioning tasks. 

Before Proceeding 

Before you begin to assemble your new boat you should become familiar with the different sail 

control systems and associated hardware. All running rigging and loose deck hardware items are 

shipped from the factory in parts boxes complete with part inventory sheets. To help you 

properly install these items please refer to the rigging and hardware sections and diagrams in 

this guide. 

Commissioning Checklist -‐ will help you double check that the J/105 is assembled properly and all 

systems and rigging are functioning properly. If a boatyard other than an authorized J/Boat 

dealer is performing the work, review this list with them to establish what needs to be done and 

by whom. 

Topsides -‐ wash off all dirt and grime accumulated from delivery. Use only non-‐abrasive 

cleansers on the gelcoat. Then apply a coat of high quality car or boat wax to prolong the life and 

sheen of the gelcoat. 

Bottom -‐ Bottom preparation is critical to long-‐lasting enjoyment. To ensure a professional 

finish, carefully review the paint manufacturer’s recommendations for preparing the bottom. Be 

sure that there is a healthy amount of epoxy primer (using paint manufacturer build-‐up 

recommendations) to cover the keel PRIOR to final coating of bottom paint. 

Chainplates -‐ are custom manufactured of polished stainless steel. Shroud chainplates are 

mounted directly to the main bulkhead. The backstay chainplate is bolted to a reinforced area of 

the transom. 

Toe Rails -‐ toerails are included at the deck edge forward of the mast and in the cockpit for the 

helmsman aft of the wheel. 

Stanchions & Pulpits -‐ are designed for proper offshore safety as well as to facilitate access to the 

boat. Optional are lifeline gates to port and starboard. The (3) standard stern lifelines are 

equipped with quick release Pelican hook fittings. All stanchions are 1” diameter stainless steel 

and are secured into their bases with machine set screws. 

Lifelines -‐ The upper and lower lifelines are 5/32" 1x19 wire in accordance with ORC safety 

regulations. They run the length of the boat and are fastened at either end by stainless forks and 

turnbuckles. Each lifeline is clearly marked for easy installation. The installation is as follows: 

• Insert all stanchions into the sockets provided along the edge of the deck. Secure each 

stanchion in place by tightening the two screws in each base. We recommend that you 

dip the screws in blue Loctite or sealant before securing, so they don’t work themselves 

loose over time.


• Install all lifelines without tightening the turnbuckles. Remove the eyes at the ends of the 

lifelines and thread them through the stanchions. If the boat is equipped with the 

optional lifeline pads, thread the lifeline through these prior to attaching to the stern rail. 

• Finish off the job by tightening the turnbuckles, and taping off the turnbuckle “split rings” 

(or cotter pins) for a secured finished appearance. 

Skylight Ventilation Hatches -‐ are made of extruded anodized aluminum and scratch-‐resistant 

acrylic cover. The hatch comes equipped with a ventilation position and 180 degree articulation. 

Fixed Ports & Optional Opening Ports -‐ are made with extruded aluminum frames and smoke 

colored acrylic. The optional opening ports can maximize interior comfort and cross-‐flow 

ventilation. There are four fixed standard ports and two optional opening ports to replace the aft 

fixed aluminum ports. 

DO NOT PERMIT ACETONE OR OTHER HARSH CLEANSERS TO GET ON PORTS OR HATCHES AS THEY 

MAY DAMAGE THE FINISH & CLARITY OF SOME DECK HARDWARE. 

Deckhouse Handrails -‐ Stainless handrails are standard for secure maneuvering on deck and ease 

of maintenance. 

Winches -‐ Standard winches are aluminum self-‐tailing models from Harken. The location of these 

winches facilitates sailing with one or two aboard. Each is geared to match the load requirements 

of the specific task. 

Standard Steering System 

The steering system is carefully engineered to provide finger-‐tip control. This is achieved by 

utilizing high quality Jefa rudder bearings. The rudder itself is made of unidirectional glass, with 

two molded halves bonded together, and a highly reinforced fiberglass shaft. It's engineered to 

withstand tremendous shear loads for storm conditions. 

Standard Tiller -‐ is a molded, composite part bolted to a custom stainless steel tiller head mounted 

to the top of the rudder shaft. The Spinlock adjustable hiking stick is attached on the forward 

end of the tiller to enable the helmsman improved visibility sitting further outboard. 

Optional Wheel Steering System 

Pedestal & Wheel -‐ is custom molded fiberglass. Inside the "compass cowl" is a standard Lewmar 

sprocket that is connected to a chain and 7x19 wire to the custom aluminum quadrant. 

Adjustment to this linkage is achieved by a set of turnbuckles connected to the steering wire. 

These can be accessed through the lazarette locker to starboard of the rudder post. Wheel is a 

Lewmar wheel with an elkhide cover. 

Rudder Stock Seal -‐ is located at the top of the lower rudder bearing. It is a simple flexible boot 

type design that prevents water from entering the hull. If tiller steering is installed, the fiberglass 

rudder tube is continuous between the hull and the deck.


Emergency Tiller -‐ is installed by removing the access plate, and placing the base of the tiller over 

the head of the rudder stock. Fit the emergency tiller NOW to see how the system works BEFORE 

you get caught in a situation where you may not have time! 

Before Launching -‐ check the system of cables, quadrant, and sheaves to ensure they are working 

smoothly. If the steering seems loose, tighten the turnbuckles by hand and re-‐pin them. Beware 

that you do not over-‐tighten the cables. Please note that your steering should be checked 

periodically for "tightness" and for presence of properly bent cotter-‐pins. 

Rigging Systems 

The running and standing rigging items supplied with your boat are designed for efficiency. A 

wealth of racing and cruising experience has gone into the deck layout to make sailing and boat 

handling safe and easy to handle by a couple or a racing crew. 

The most unique system on your J/105 is the bow sprit system for the asymmetric spinnaker. 

We believe this system is a major improvement over conventional systems, so let's start by 

explaining how it works! 

Carbon Fiber Bow Sprit -‐ The carbon fiber bow sprit is custom made and is designed to withstand 

the loads associated with the class asymmetric spinnaker without any additional support. The 

pole consists of a carbon tube faired smooth and finished with a clear Awlgrip high gloss paint, 

and two end fittings. The forward end fitting has a "U" bolt which serves as the attachment point 

for the tackline/snuffer block. The aft end fitting houses all hardware necessary for the adjuster 

line and shock cord retrieval system. 

Bow Sprit Launching Line -‐ The control line to pull out the bow sprit is designed to be adjusted 

without leaving the cockpit. The line is dead-‐ended to the outboard pad eye on the forward most 

bulkhead in the forepeak. The line then leads through the thru-‐pole blocks on the aft end fitting 

of the carbon fiber pole (be sure the "U" bolt on the other end of the pole is up), forward through 

a block on the inboard padeye on the forepeak bulkhead, then under deck through the bullseye 

fairleads, the main bulkhead, and finally to the cam cleat mounted on the aft side of the cabin top 

to starboard 

Asymmetric Shock Cord Retrieval System -‐ The shock cord system allows the pole to automatically 

retract when you uncleat the control line. Set up as follows: attach one end of shock cord to the 

pole end fitting pad eye, lead through the Harken double block mounted on padeye on the 

hanging locker bulkhead, then lead cord through the bullseye on the bottom of the pole end 

fitting to the forward single Harken block, back through the bullseye, around the becket of the aft 

block, and secured to the back end of the pole. You may need to experiment once or twice to get 

the appropriate tension on the shock cord. It should be relatively easy to extend the pole fully, 

and when released, should quickly retract into the boat. If you do not already have a preventer 

line, put a knot in the cockpit control line behind the cam cleat (in the cockpit) to prevent the 

sprit from banging into the bulkhead when released. 

Harken Headsail Furling -‐ The Harken Unit 1 furler is provided with the boat standard and 

requires assembly prior to installing the mast. A complete instruction manual is included with 

this hardware detailing the proper procedure. The pin-‐to-‐pin headstay length necessary to 

complete this task for the J/105 is 12929mm or 42’ 5”. The provided pre-‐feeder should be lashed 

and taped halfway between the feeder gate and the lower extrusion leg.


Mast -‐ Rigging the J/105 mast is a common procedure, and best handled by a qualified marine 

rigger. All spreaders, shrouds, and halyards are installed and properly taped and secured. Be sure 

all mast related electronics and wind indicators are properly wired and installed prior to 

stepping the mast. After stepping the mast it is VERY IMPORTANT to properly brace the mast 

within the mast collar PRIOR to sailing with the provided Pre-‐Molded Spartite mast wedge. We 

also recommend that a small cord is tied and taped approx. 24” above the lower spreader 

between the intermediate shroud and upper shroud if you plan to sail with any type of spinnaker. 

Simply tie this line to each shroud (allowing for some slack) and tape ends over with rigging tape. 

This prevents the spinnaker (during a take-‐down) from potentially dropping into the V that is 

formed at the lower spreader between these shrouds. 

Hydraulic Backstay -‐ The J/105 is equipped with an integral hydraulic backstay to help you fine 

tune your rig and sails for optimum performance. This hydraulic unit is simple to operate, easy 

to maintain, and highly reliable. The cylinder is affixed to the backstay tang on the transom and 

to the backstay. In order to attach the backstay, you must pull out the SS shaft and fully extend it. 

Boom -‐ Run the reef lines so the red line (port) is led through the port sheaves and the green line 

(starboard) is led through the starboard sheaves at both the outboard end and the gooseneck. 

The starboard reef doubles as the cunningham. 

Boom Vang -‐ The standard boom vang is a mechanically operated spring loaded boom vang with a 

block and tackle purchase system. This vang system allows for quick and easy adjustment and 

also acts as a boom topping lift. The vang is affixed to the vang plate welded underneath the 

boom and to the mast at the vang gooseneck located just above the mast collar. See the vang 

operating instructions for how to adjust the internal spring for best results. 

Sail Control Systems 

After stepping the mast and connecting the boom, vang, roller-‐furler, and integral backstay, rig all 

halyards and the remaining sail control systems on deck. 

Main Halyard -‐ exits the mast on the port side, runs through a turning block at the mast collar, 

through the inboard port organizer block and then aft through the port double stopper (inboard 

hole) and finally to the halyard winch. The tail end is stored in the supplied line bag to be 

mounted outboard and forward of the stopper. 

Jib Halyard -‐ exits the mast to port, leads through the forward mast base block, aft to the outboard 

sheave on the organizer block, through the outboard stopper hole, and store tail in line bag. 

Spinnaker Halyard -‐ exits the mast to starboard and leads to the outboard sheave and stopper. 

Mainsheet Traveler -‐ is a Harken low friction system. The 3:1 purchase system on each side 

controls a Harken Windward Sheeting Car mounted on midrange track (see diagram). 

Outhaul -‐ is adjusted at the cleat on the underside of the boom and comes pre-‐assembled. 

Cunningham -‐ The cunningham doubles as the starboard reef line. To set it up as a cunningham 

simply tie a knot at the boom end tail of the reef line. The line leads forward to the sheave at the 

gooseneck, up to the cunningham block/hook back down through a bullseye on the mast, down 

to the mast base block and aft to the inboard stopper.(see diagram). To use the continuous reef


system simply run the boom end tail through the clew reef grommet, back down around the 

boom and tie a bowline. 

Mainsheet -‐ is a 24:1 system with a 6:1/4:1 set-‐up (see diagram). The system is designed to allow 

easy adjustments of the mainsheet. The location of the traveler also facilitates single-‐handed 

sailing and adjustments. The fixed centerline cleat base rotates to port and starboard for a 

proper lead. Be sure to put a "stopper knot" like a figure-‐eight at the end of the mainsheet. 

Jib Sheet -‐ is continuous and attaches to the roller-‐furler headsail by a simple knot, leads to the jib 

block on the track, aft to the lower sheave of the double turning block on the rail and finally to 

the primary winch. 

Spinnaker Sheets -‐ lead from the clew of the spinnaker aft outside the lifelines through the 

spinnaker sheet blocks (shipped loose) turning forward to the upper sheave of the double 

fairlead blocks along the rail and then to the primary cockpit winches or secondary cabin-‐top 

winches.


Commissioning Checklist 

Pre-Launch 

___ Read equipment owner manuals 

___ Pre-rig mast and check installation of: 

• halyards 

• blocks 

• electronics 

• shrouds 

• spreader end chafe guards 

• shroud spinnaker protection 

• lifeline pins 

• Mast Boot 

___ Pre-rig boom 

___ Bottom painted or touched up 

___ Check propeller/strut/zinc 

___ De-winterize engine and check status of: 

• engine oil/ filter 

• coolant level 

• transmission fluid level 

• water intakes/filter 

• fuel lines/filter 

___ Check battery charge 

___ Check all hose clamps, tighten as required 

___ Close all seacocks 

___ Wire tie wooden plugs near all thru-hulls 

Steering System (Wheel) 

___ Attach Wheel 

___ Check steering cable tension 

___ Test fit emergency tiller 

___ Check rudder stops 

Launch 

___ Check for leaks 

___ Check seacocks 

___ Check stuffing box 

Engine Start 

___ Read engine owner’s manual 

___ Open raw water intake seacock 

___ Check fuel 

___ Start engine 

___ Check exhaust for cooling water flow 

___ Check oil press., water temp., charging gauges 

___ Check transmission- forward/reverse 

___ Check stuffing box 

Step Mast 

___ Locate mast step in middle of range and tighten bolts. 

___ Hoist spar and lower into boat 

___ Attach headstay to stemhead fitting 

___ Attach backstay and cylinder to backstay plate 

___ Attach all shrouds and hand tighten 

___ Install mast wedges and boot 

___ Connect mast junction box wires 

Rigging 

___ Install boom 

___ Lead all halyards to stoppers on cabin top 

___ Rig reef lines 

___ Install and connect boom vang 

___ Dock tune spar per tuning guide 

___ Rig bow sprit launching guide 

Loose Gear 

___ Fenders and lines 

___ Dock lines 

___ Winch handles 

___ Ignition/boat keys 

___ Bilge pump handle 

___ Mast wedges ready 

___ Double-check sling locations and mark 

___ Anchor, chain and rode 

___ Fire extinguishers installed 

___ First aid kit 

___ Coast Guard Required Safety Gear 

Systems Check 

___ Fill fuel tank 

___ Check operation of electrical systems and pumps 

___ Check sailing electronics 

Trial Sail 

___ Raise and lower sails to check for fit 

___ Monitor engine performance and check stuffing box 

___ Check bilge for leaks 

___ Check sailing electronics 

___ Check reef points and lines 

___ Check for steering cable stretch (wheel only)


Tuning the J/105 Rig 

Following is a general guide to tuning your J/105 mast. Please consult your sailmaker for “fine-tuning” 

the mast to match the sails. 

With the standard length J/105 headstay and the mast step situated in the middle, the mast rake 

(as measured from the back of the mast at deck level to a plumb on the main halyard) should be 

approximately 30 inches. Several owners have opted to install an additional toggle at the top of 

the headstay, and then shorten the drum turnbuckle so to lower the drum as close as possible to 

the deck. According to J/105 Class Rule 7.4 “the headstay system length, measured between the 

centerline of the headstay pin on the mast to the intersection of the stem line and the sheer line 

at the bow, shall not be greater than 13035mm nor less than 12985mm. We recommend the 

maximum allowed headstay length for most conditions. 

The upper shrouds are attached to the outer chainplate hole. The lowers are connected to the 

inner hole. The intermediates are secured in the forward hole. Begin by hand tightening the 

shrouds, being careful to keep the mast centered aloft. Check alignment by hoisting a tape 

measure up the main halyard and comparing measurements to the port and starboard 

chainplates. When the top of the mast is centered, sight up the mast track to check for alignment 

of the lower part of the mast. Hand adjust the shrouds as necessary to center the mast. 

After the rig is centered and hand tight, we recommend additionally tightening the shrouds the 

following number of turns: 

Upper Shrouds: +11 turns 

Lower Shrouds: + 2 turns 

Intermediates: 

+ 8 turns 

You’ll find it easiest to tighten the upper shrouds if you pump the backstay down 2-‐3 inches first 

to relieve load. Under sail, it is easiest to adjust only the leeward shrouds, then tack to adjust the 

other side. 

Once you have initially tuned your J/105, then go sailing in a brisk breeze, spending equal time 

on both tacks. Even though rod rigging is the lowest stretch material possible, you’ll still see a 

little loosening after the initial breaking in period. Be sure to sight up the mast while it is under 

load to see if it remains in column.


Important Commissioning Follow-‐up 

The initial sea trial period, or the first 30 days after launching a new boat always requires 

important follow-‐up by the owner including sail fit checks, rig tuning and adjustments, 

instrument and compass calibration, maintenance and systems checks, etc... Your dealer and 

their support staff and other local suppliers will help you with this process. It is imperative that 

the following areas of the boat are inspected and confirmed to be operating properly after the 

initial 30 days. 

30 Day Inspection List 

PROPELLER SHAFT ZINC -‐ Inspection of the shaft zinc is very important in the first 30 days 

following launch. Accelerated zinc corrosion may indicate an electrical wiring problem onboard 

or stray current from a nearby boat. RAPID CORROSION OF THE SHAFT ZINC SHOULD NEVER 

BE IGNORED. IMMEDIATE ATTENTION IS REQUIRED BY THE OWNER & DEALER. Failure to 

respond to this important sign of galvanic corrosion may lead to severe damage to underwater 

metals. 

STEERING CABLES ON WHEEL-‐SUPPLIED BOATS – Steering cables are known to stretch after 

initial setting and usage. The following technique is helpful for adjusting cable tension in the 

system. A top quality roller chain to wire steering system can be kept in “as new” sensitivity by 

keeping the wire at a correct tension. To check for proper wire tension, lock the wheel in position 

by using the pedestal brake, or by tying off the wheel. Cable tension is best when you cannot 

move the quadrant or drive wheel by hand with the wheel locked in place. Over tightening will 

greatly reduce the sensitivity of the system. When leaving your boat at her mooring or slip, make 

sure that your wheel is properly tied off. DO NOT LEAVE THE STEERING SYSTEM TO FREE 

WHEEL. 

MAST, SPARS, RIG & RIGGING – The standing rigging terminations will seat and the SS rod will 

stretch during initial sea trials. It is prudent to inspect all fittings, terminations, turnbuckles, 

halyards, and mast wedges, and to look for any signs of unusual wear after sea trials. Checking 

and adjusting rig tuning is also recommended. 

The following ship systems must also be tested for proper operation: 

• ENGINE, THROTTLE CONTROL & FUEL SYSTEM. 

• FRESH WATER SYSTEM. 

• HEAD SYSTEM. 

• MANUAL AND ELECTRIC BILGE PUMP SYSTEMS. 

Finally: 

• REVIEW PROPER SAFETY EQUIPMENT – confirm all required safety gear is onboard and 

in working order. 

• CHECK ALL LIFELINE TERMINATIONS & TURNBUCKLES – Confirm cotter pins in 

turnbuckles and set screws are secure in all stanchion bases. 

• RE-‐VISIT & REVIEW COMMISSIONING CHECKLIST 

ANY PROBLEM AREAS IDENTIFIED ABOVE MUST BE ADDRESSED PROMPTLY.


Diagrams, Layouts, & Schematics 

Running Rigging & Deck Hardware Layout


Mainsheet & Cunningham Diagram


Steering System


Fuel & Exhaust System


Thru-‐Hull & Seacock Locations


Manual Fresh Water System


Head & Holding Tank Schematic


12V DC Layout


Battery Wiring System


Lightning/Bonding System


Engine System 

The engine and fuel system is engineered to be conveniently accessible for repairs and general 

maintenance. Located behind the companionway ladder, there is access on the aft sides (through 

the cockpit lockers) and in front of the engine from which important functions can be reached; 

including water strainer, fuel injectors, fuel filter, fuel primer, expansion chamber, and 

alternator. 

Before starting the engine read the engine manufacturer's owner's manual for proper break-‐in 

and operating procedures. Once the engine is running, inspect it for any discrepancies, like oil 

leaking, excessive water leaks, or anything out of the ordinary. 

Drive Train 

• Engine Control Panel -‐ is mounted in the cockpit. It contains the starter, stop button, 

warning lights, and gauges. The combination throttle/gearshift is mounted on the 

cockpit wall. Double-‐check all mechanical connections between engine and on-‐deck 

equipment. 

• Engine Bed -‐ is constructed of highly reinforced fiberglass. This provides a superior 

mount over wood and is also rot-‐proof. The engine sits on heavy duty rubber shock 

mounts to help isolate the engine vibration from the boat. Check to see that the engine is 

sitting correctly on them and the bolts tightly secured. 

• Neutral Safety Switch -‐ the J/105 is equipped with a neutral safety switch and the engine 

will not start without the throttle control in a proper neutral or advanced neutral 

position. 

This is the complete system that propels your boat. It includes the following components: 

coupling, stuffing box, shaft log, shaft, strut, and the propeller. 

• Transmission -‐ is attached to the aft end of the engine and houses the reduction and 

reverse gears. These gears generally need little maintenance, but the oil level should be 

checked periodically. 

• Stuffing Box -‐ is aft of the engine where the propeller shaft passes through the hull. It is a 

waterproof housing consisting of a rubber "jacket" attached to the tube and a brass 

bearing with hose clamps. When the engine is running, check to see that intermittent 

drips of water appear where the shaft enters the stuffing box. If the drips are a 

continuous stream, i.e. more than one every ten seconds, you must tighten the 

compression nut on the forward end of the stuffing box. This requires two large pipe 

wrenches to tighten the forward nut over the aft "core nut." It should not get hot when 

running. 

• Propeller -‐ is a MARTEC folding prop of high quality bronze alloy. Check to see that the 

blades on the prop open almost perpendicular to the shaft. The prop is simple to care for 

and can withstand years of hard use. However, there are a few easy precautions which 

can prolong its life:


o 

o 

o 

o 

Coat it with an excellent silicone grease film. 

Check to see that the joints in the folding prop have a good coating of waterproof 

grease. 

Check that all cotter pins are bent over properly. 

Check that the blades are smooth. 

• Prop Shaft -‐ is stainless and is supported at the inboard end by the shaft coupling and at 

the outboard end by the strut containing a rubber "cutlass bearing." Before launching 

attach a "shaft zinc" to minimize corrosion. The zinc should be replaced every time the 

boat is hauled. Check the "cutlass bearing" periodically for wear and tear. If it is loose, 

replace it. 

• Engine/Shaft alignment is set by the builder to ensure that the engine, shaft, stuffing box, 

and prop are properly adjusted to minimize engine vibration. If there seems to be 

excessive vibration, notify your dealer and have them investigate. 

Fuel System 

The Fuel System is located centrally in the boat for effective weight distribution. It consists of the 

fuel tank, fill hoses and caps; fuel lines and filters and the vent. Use only Diesel fuel in the system. 

• Fuel Tank & Line -‐ run from underneath the port main cabin settee, under the cabin sole 

and up to the fuel primer pump. From there, fuel flows into the injectors. The tank is 

aluminum, baffled to prevent fuel slosh, and vented overboad. For a layout, please see 

the Fuel System diagram. 

• Fuel Level Gauge -‐ is located on top of the tank. The gauge reflects level (height) of fuel in 

the tank, not the quantity. Try to maintain a minimum level of 1/2 tank filled at all times. 

• WARNING-‐ IF YOU ARE MOTORING AND HAVE LESS THAN 1/3 TANK OF FUEL, BE 

CAREFUL OF HEELING THE BOAT TO PORT, OR YOU WILL RISK AIR GETTING INTO THE 

FUEL LINE. Familiarize yourself with the bleeding procedure instructions provided with 

the Yanmar paperwork. 

• Fuel Line Shut-‐Off Valve -‐ sits atop the tank at its aft end. Since diesel engines require 

bleeding after they have been deprived of fuel, it's important that the shut-‐off valve be in 

the "ON" position (lever parallel to piping) anytime the engine is started. 

• Fuel Tank Access Plate -‐ is atop the fuel tank and provides access inside to clean the tank 

or check the fuel gauge.


Cooling System 

The J/105’s engine utilizes both a “closed” cooling system, in which a mixture of fresh water and 

antifreeze is circulated within the engine, and a “raw water” system, in which a heat exchanger 

supplies a constant flow of outside water, pumped in through the raw-‐water intake, to cool the 

coolant mixture. 

• Coolant system -‐ The filler cap (it looks like a radiator cap) for the freshwater-‐and-antifreeze 

cooling system is located on top of the engine manifold. Check the coolant level 

of the manifold and the coolant sub-‐tank aft of the engine, (check when the engine is 

cool). When adding coolant, follow the engine manufacturer’s recommendations for the 

proper fresh water/antifreeze ratio. In climates where freezing may occur in winter, test 

the coolant mixture for freezing point. Add coolant as needed if the system is not drained 

for winter storage. 

• Raw-‐water system -‐ Located in the engine compartment, the J/105’s raw-‐water strainer 

helps prevent clogging of the raw-‐water cooling system and overheating of the engine. 

Check the strainer basket often to insure that the flow of cooling water is unimpeded. To 

clean: Ensure the engine water intake thru-‐hull is closed. Check that the lever is 

perpendicular to the intake. Unscrew the top of the strainer and remove the basket from 

inside the plastic case. Wash thoroughly with water or replace with a new one if badly 

soiled. Reinstall the basket and be sure it is seated properly in the bowl. Then reinstall 

the lid tightly. 

Exhaust System 

The J/105 is equipped with a water-‐injected water-‐lift exhaust system that dissipates exhaust 

heat and acts as the exhaust muffler. If the flow of cooling water is interrupted and the engine 

overheats severely, the rubber hose coming from the engine exhaust elbow may melt. Always 

check this hose after an occurrence of overheating. 

Cooling water can accumulate in the bottom of the water-‐lock muffler; when de-‐commissioning 

your boat for the season, the muffler either should be drained by unscrewing the drain plug on 

the bottom of the muffler or antifreeze should be added so that residual water doesn’t freeze. 

If the engine does not start after a prolonged period of cranking over (starting), be sure to drain 

the pot or exhaust loop. Water accumulates here and may fill enough to flow back into engine 

manifold if engine does not start. 

General Hints To Avoid Problems 

• Monitor brightness of cabin lighting and charge battery as required by running engine. 

Batteries are charged when running the engine. 

• Stop engine with the start/stop switch. 

• NEVER turn battery switch to OFF position while engine is running as this could damage 

the alternator. 

• For best performance and fuel economy a cruising R.P.M. of 2,200 -‐ 2,800 works well. 

Please refer to the Yanmar manual for recommendations. It is good practice to vary RPM


levels periodically when cruising under power for a long distance. Be sure to thoroughly 

read and follow the manufacturer’s manual for proper break-‐in procedure for the 

standard Yanmar Diesel engine. 

• Do not run engine at full throttle for sustained periods, as breakdowns may occur. Most 

importantly, find an RPM that runs smoothly and follow the Yanmar guide. Avoid 

"vibrating" RPM speeds when possible. 

• Keep engine gear shift lever in "REVERSE" position while sailing to prevent possible 

"free-‐wheeling" of prop 

• CAUTION: The J/105 engine is very quiet, and it is possible to forget that it is running. 

Before shifting the gear shift lever to lock the shaft for sailing, double check that the 

engine is turned off. 

Engine Safety Precautions 

Due to high temperatures it is recommended that after running the diesel for more than two 

hours you reduce speed to idle and allow excess heat to dissipate for five to ten minutes prior to 

shutting the motor off. 

The most common cause of trouble is contaminated or dirty fuel. Your boat is equipped with a 

primary fuel filter located in the engine compartment and a secondary filter on the engine. The 

wise skipper carries replacement filter cartridges. Familiarize yourself with the bleeding 

procedure for the engine and you should learn how to bleed it yourself. The procedure only 

takes a few minutes after you are acquainted with it, but can be exasperating to the uninitiated.


Bleeding The Engine 

Reprinted from Mac Boring Service Bulletin: 

This bulletin contains helpful information for bleeding the fuel system of a Yanmar Diesel and 

other small diesels as well. Please post where your field service personnel can review. 

Since the presence of air in the fuel system anywhere between the fuel tank and the injector 

will lead to a no start or erratic running condition, always bleed the air from the system when 

the fuel system is disassembled, filter changed or if run out of fuel. 

1. Make sure fuel tank off is in "on" position. 

2. Bleed the air from fuel filter. Loosen the air bleed screw at the top of the fuel filter body 

and operate the manual handle the lift pump until the air bubbles completely expel in the 

fuel flowing from the filter. 

3. Bleed the air from the fuel return pipe. Loosen the connector bolt of the fuel return pipe 

installed on the fuel injector, and bleed the air by operating the manual handle of the lift 

pump. (If there is more than one injector, bleed the one at the end of the line). 

4. Bleeding the air from the fuel line -‐ (line from the filter to the injector pump). Loosen the 

air venting screw at the injection pump and operate the manual handle of the lift pump 

until all the air bubbles are out. 

5. Bleed the air from the fuel injector. Loosen the nipple on the fuel injector side, set the 

throttle to half and the decompression lever to the decompression position and crank 

engine. When no more bubbles appear in the fuel flowing from the end of the injection 

pipe, re-‐tighten the nipple. 

THIS BULLETIN IS FOR INFORMATION ONLY AND NOT AN AUTHORIZATION FOR REPAIRS 

Starting The Engine 

1. Turn the battery selector switch to ALL. Turn off all electronic instruments to avoid a 

voltage spike to the instruments while cranking the engine. 

2. Make sure that the throttle control is in neutral, or advanced neutral. 

3. Turn the ignition key to the ON position (if so equipped). The engine-‐alarm buzzer will 

sound and the warning lights for low oil pressure and charging will light up. (The alarm 

and warning lights will continue until the engine starts or the key is turned off.) 

4. If the engine-‐alarm is working correctly, continue to turn key. Release immediately when 

the engine starts. If the engine does not start in 10 seconds, turn off the key. Advance the 

throttle slightly (in neutral), wait 10 seconds, and repeat steps 3 and 4. 

5. When the engine starts, the oil-‐pressure and charging warning light will go out and the 

engine-‐alarm buzzer will stop. If they do not, stop the engine immediately.


6. Once the engine starts, set the throttle at about 1,000 RPM. If all engine indications are 

normal, warm up the engine for 10 minutes. 

7. Briefly test the operation of FORWARD and REVERSE gears at the dock with the dock lines 

in place. 

CAUTION: If the engine does not start after a pro-‐longed period (do not exceed 10 seconds at a 

time) of cranking, be sure to drain the water-‐lock muffler and exhaust loop. ACCUMULATED WATER 

IN THE MUFFLER MAY FLOW BACK INTO THE ENGINE MANIFOLD AND DAMAGE THE ENGINE IF THE 

MOTOR IS CRANKED FOR A PRO-‐LONGED PERIOD AND DOES NOT START. 

IMPORTANT: Check that a flow of raw-‐water cooling water is exiting from the transom. If cooling 

water is not being discharged, the engine will overheat: shut down the engine immediately. 

Check that the raw-‐water strainer basket is free of blockage. Check that the raw-‐water engine-intake 

valve is open on the seacock. If necessary, check underneath the hull to make sure that the 

raw-‐water intake seacock is not blocked. 

Shutting Down The Engine 

1. Move the throttle to the IDLE (vertical) position. 

2. Run the engine at IDLE long enough to allow the engine to cool down. 

3. Push the button on the engine instrument panel until engine stops. 

4. When the engine-‐alarm sounds, turn the key OFF. 

IMPORTANT: Do not use the ignition key to shut down the engine. Do not stop the engine with 

the decompression levers except in an extreme emergency. If decompression lever is used to 

shut down the engine, fuel will spray out and accumulate on top of pistons, creating a danger of 

explosion the next time engine is started. 

Fueling 

When taking on fuel, follow these safety precautions: 

1. Secure your boat to the dock using bow, stern, and spring lines. 

2. Turn OFF all mechanical and electrical equipment, including the engine, battery selector 

switch, cabin lights, and electronics. 

3. Remove the fuel-‐fill deck plate plug; clean the threads of both the plug and deck plate so 

that no dirt falls into the filler opening. Place the fuel hose nozzle into the fill pipe. 

4. Fill the fuel tank slowly. Do not overfill the tank. Because marine fuel expands with an 

increase in temperature, fill the 18-‐gallon tank to only 95% of its capacity. If you cannot 

see the fuel pump, ask the attendant or a crew member to call out the total gallons. 

IMPORTANT: If the fuel tank is overfilled, fuel will leak out the tank vent located on the 

transom. Be ready to contain and clean up any spillage immediately.


5. After fueling, replace the fuel-‐fill deck plate and clean any spillage. Check belowdeck for 

fumes and check the bilge for fuel leakage. If fumes or liquid fuel are present, correct the 

situation before proceeding. Open all hatches and ports to ventilate the boat. 

IMPORTANT: In the event of a serious fuel spillage, STOP FUELING IMMEDIATELY. Replace the 

fuel-‐fill deck plate and notify the attendant. Wash all traces of fuel or source of fumes; ventilate 

the boat. Leave the fuel dock only when you are completely certain that a potentially dangerous 

condition does not exist. 

Engine Maintenance 

Check the engine, batteries, and engine mounts once a month. Ensure the engine is fastened 

securely to the engine mount frames and look for any problems, such as fuel or oil spillage. If you 

need help, consult a professional marine mechanic or a licensed Yanmar repair mechanic. 

Run the engine frequently and at occasional high speeds, even if it is not in gear. One reason why 

sailboat engines may burn out within a few years is that they are run infrequently and lubricating 

oil is not thoroughly and evenly distributed on all moving parts. Be sure to check oil and coolant 

levels often. If you have any doubts about the purity of the fuel you are buying, use a strainer to 

filter out water and dirt.


Plumbing Systems 

General 

The plumbing systems in your J/105 consist of fresh water, manual and electrical bilge pumps, 

and a Raritan head (toilet). This section will describe their locations and how they operate. 

Manual Fresh Water 

• Water Tank -‐ is made of polypropylene, is collapsible, and is simple to install. Simply 

attach the hose from the foot pump to the tank. 

• Optional Water Tank -‐ Part of the Systems Group package, this 20 gallon tank is made of 

rotationally molded polyethylene. Entire capacity may not be usable depending upon 

trim, loading, filling and draining points. Connected to it are the following hoses: a) fill 

hose -‐ located on the tank top and connecting to the deck water fill pipe; b) feed hose -‐ 

located along the tank bottom connecting the water system to the manual pumps; c) vent 

hose -‐ internal and leads under the sheer line into the bow compartment. 

Thru-‐Hulls & Seacocks 

All Seacock fittings are Forespar Marelon. For safety reasons, we recommend that you attach 

with wire or wire-‐tie an appropriate size tapered wooden plug in the vicinity of each of these 

fittings in the event of a hose or valve failure. The fittings each have valve-‐handles. To reduce 

confusion, remember the long end of the handle indicates the direction of flow. Please refer to 

the Seacock and Thru-‐Hull diagram for a complete layout of locations and sizes. 

Pump Systems 

Pumps are easy to maintain and just as easily forgotten...they always happen to seize up when 

you need them most. Consequently, take care to keep their screens clean and rubber 

gaskets/bellows working correctly. There is one manual and one electric bilge pump system 

installed standard in the J/105. Two pump intakes are located forward in the keel sump under 

the main cabin centerline floorboard. 

• Manual Bilge Pump: The manual bilge pump is installed on the cockpit wall and operated 

by opening the cover/handle and using an up and down manual pumping action. Bilge 

water exits the boat from the manual pump through the transom. 

• Electric Bilge Pump: is wired direct with an in-‐line fuse to the battery switch, so it is 

always "on." This useful feature helps eliminate any accumulation of water in the bilge. 

The switch is located near the electrical panel. The switch has three positions: ON, OFF, 

and AUTO for self tending when you are not on the boat. Bilge water exits the boat from 

the electric pump through a hose that loops up to a siphon break and then to the 

overboard through-‐hull fitting under the head sink. 

• Sink Drains empty directly overboard through a seacock fitting beneath the galley sink.


Safety caution: Owners MUST leave the three position pole switch on the bilge pump panel (located 

in the nav station area) in the AUTO position in order for the bilge pump to perform properly. 

Please refer directly to pump manuals and/or web site information for more about best practices 

and maintenance of this component. Finally, it is prudent seamanship to carry replacement parts 

for all onboard pumps. 

Warning the bilge pumping system is not designed for damage control. The combined capacity of 

the system is not intended to drain the craft in the case of accident or damage. 

Head System 

The J/105 is equipped with one certified Raritan PHII marine head which is capable of 

discharging effluents into the standard 45 liter (12 gallon) holding tank or overboard. The 

system is easy to operate and with correct usage and proper maintenance, will provide many 

years of use. IMPORTANT -‐ Owners should familiarize themselves with all local and federal 

regulations regarding proper discharge and avoid inadvertent discharge at all times. A Y-‐valve is 

fitted to the discharge line in order to direct the discharge flow to either the holding tank or 

overboard. It is shipped from the factory bolted into place such that the flow defaults into the 

holding tank. 

Before operating the HEAD, ensure you have read its manual thoroughly and understand the 

proper procedures. Silly mistakes can cause severe “head” aches at the worst possible time!. And 

a word to the wise 

PLEASE TRAIN YOUR GUESTS ON HEAD OPERATION. NEVER ASSUME THEY KNOW HOW TO 

USE IT. 

The head is a large pump which takes in seawater and flushes waste into the holding tank or 

overboard. The water intake seacock is located under the V Berth, and the discharge seacock is 

under the head sink. Remember the open/closed positions on these thru-‐hulls. It is good 

seamanship to close both the intake and discharge seacock when not in use. 

When seawater and effluent are pumped through the head, they’re pumped into the holding tank 

by the action of pumping the toilet handle. The waste discharge fitting on deck is provided so a 

Shoreside pump-‐out station can empty the tank. Care should be taken not to overfill the holding 

tank as effluent can block the vent hose and may damage the tank... or worse, burst the hose. If 

the toilet is difficult to pump, check to see if the holding tank is overfilled. “When in doubt, pump 

it out!” A great resource for understanding and maintaining a marine head system is a book 

called “Get Rid of Boat Odors” by Peggie Hall -‐ Seaworthy Publications. 

Recommended Head Cleaning Solutions: 

Holding Tank -‐ Use fresh water and one gallon of white vinegar solution… flush out twice. There 

are also several holding tank treatment solutions available through local marine stores. 

Head -‐ refer to the head owner manual for proper cleaning solutions and maintenance. 

Pumping a quart of fresh water type anti-‐freeze through the head system and hoses will prevent 

the seals and equipment from cracking. The following hoses are connected to the tank.


• Waste Discharge Hose from the head 

• Pump-‐out Hose leading to the deck fitting 

• Vent Hose to vent the tank overboard. 

The holding tank must be pumped out before winter storage to avoid potential damage and the 

system shall be empty during storage at freezing temperatures.


Electrical System 

The following section describes the electrical system aboard the boat, how it operates, where it 

leads, and how to avoid trouble. Please read this section more than once and refer to the 

electrical diagrams included in this manual. For wiring code information please refer to the 

color code diagram. 

Never: 

• Work on the electrical installation while the system is energized; 

• Modify the craft’s electrical system or relevant drawings: installation, alterations and 

maintenance should be performed by a competent marine electrical technician; 

• Alter or modify the rated current amperage of overcurrent protective devices; 

• Install or replace electrical appliances or devices with components exceeding the rated 

current amperage of the circuit; 

• Leave the craft unattended with the electrical system energized, except automatic bilge-pump, 

fire protection and alarm circuits. 

DC Electrical System 

A 12 Volt DC electrical system is used throughout the J/105 for lighting and operation of pumps 

and various accessories. The J/105 is standard with one 12 volt 90 amp battery located under 

the cockpit aft of the engine. Optional battery capacity may be added within this locker. 

• Electrical Panel -‐ controls electric distribution with circuit breakers and switches. The 

main wiring harness runs from the back of this panel. 

• Mast Wiring Terminal Box -‐ is located on the upper portion of the bulkhead just inside the 

head to port. The mast wiring harness exits the mast just beneath the deck, and is wired 

directly into the D.C. system. The junction box is wired directly into the DC system 

through a terminal strip. Once the mast wiring is installed and mated at the junction box, 

be sure to test each function to insure proper operation. 

• Battery Switch -‐ The battery switch is located aft on the starboard settee berth face. It 

turns access to the battery ON or OFF to the main panel and the engine. The standard 

J/105 comes configured with one battery, so select BOTH on the switch. The optional 

second battery enables full use of the switch and allows one battery to be reserved 

exclusively for the engine and the ability to double up the cranking amps for cold starting 

in the BOTH position. The engine alternator will only charge the battery selected by the 

switch, so it is wise to have the switch set to BOTH should you have the additional 

battery. 

• Alternator -‐ The 60 amp alternator is attached to the engine and creates a charging 

current for the battery system when the engine is running. 

• Accessories -‐ such as navigation instruments can be added to the electrical panel and the 

12V DC system. We recommend that owners hire a qualified marine electrician to install 

electrical components. Be sure all sensitive accessories are not only grounded properly 

but that proper fuses are run off the panel.


Safety 

Fire Protection & Prevention 

Portable Fire Extinguishers 

This boat, when in service shall be equipped with at least two portable fire extinguishers in 

recommended locations below in addition to any required equipment as designated by local and 

government regulations. 

• Recommended Location 1: Starboard cockpit seat locker quickly accessible from cockpit 

& helm position. 

• Recommended Location 2: Outboard of starboard settee berth backrest cushion. 

• Type: Class B 

Servicing Of Fire-‐Fighting Equipment 

The boat owner/operator shall 

• Have fire-‐fighting equipment checked at the intervals indicated on the equipment 

• Replace portable fire extinguishers, if expired or discharged, by devices of identical fire-fighting 

capacity, and 

• Have fixed systems refilled or replaced when expired or discharged. 

Responsibility Of Boat Owner/Operator 

It is the responsibility of the owner/operator 

• To ensure that fire-‐fighting equipment is readily accessible when the boat is occupied, 

and 

• To inform members of the crew about 

• the location and operation of the fire-‐fighting equipment, 

• the location of discharge openings into the engine space, and 

• the location of routes and exits 

Cautionary Notices To The Boat Operator 

• Keep the bilges clean and check for fuel and gas vapors or fuel leaks frequently. 

• When replacing parts of the fire-‐fighting installation, only matching components shall be 

used, bearing the same designation or having equivalent technical and fire-‐resistant 

capabilities. 

• Do not fit free-‐hanging curtains or other fabrics in the vicinity of, or above, cookers or 

other open-‐flame devices.


• Do not stow combustible material in the engine space. If non-‐combustible materials are 

stowed in the engine space, they shall be secured against falling into machinery and shall 

cause no obstruction to access into the space. 

Specific Warnings 

Never 

• Obstruct passageways to exits and hatches, 

• Obstruct safety controls, e.g. fuel valves, gas valves, switches of the electrical system, 

• Obstruct portable fire extinguishers stowed in lockers, 

• Leave the craft unattended when cooking and/or heating appliances are in use, 

• Modify any of the craft’s systems or allow unqualified personnel to modify any of the 

craft’s systems, 

• Fill any fuel tank when machinery is running, or when cooking or heating appliances are 

in use, 

• Smoke while handling fuel or gas. 

Lightning Protection 

The J/105 is grounded in accordance with ABYC and industry practice. The mast, shroud 

chainplates, stemhead fitting, backstay fitting, engine, and electrical system are grounded to the 

keel. In spite of this grounding, there can be no assurance that personnel or the boat will not 

suffer injury if the boat is hit by lightning. The following are suggestions only and in no way 

guarantee safety in the event of a lightning strike. 

• If possible, remain inside a closed boat during a lightning storm. Do not contact any 

metallic objects inside or outside the boat. 

• Avoid contact with any items connected to the lightning conductive system (mast, 

shrouds, etc) and especially in a manner to act as a bridge between them (mast to shroud, 

etc). 

• Avoid swimming during a lightning storm. 

• If the boat is mildly struck by lightning, check all compasses and electrical gear to 

determine that no damage or change in calibration has taken place. 

• Check all thru-‐hull fittings, keel bolts, engine rubber gasket membrane, for leakage 

(water).


Galley Stove 

A 2-‐burner non-‐pressurized alcohol stove is part of the Systems Group Option and is in "ready-to-‐use" 

condition. It is significantly safer than older pressurized models and is a remarkably fast 

heating stove, nearly equaling the heating of home ranges. It can boil a 2 quart pot of water in 8 

to 10 minutes. Engineered with high quality stainless steel, it will last for years with proper care. 

Be sure to read the stove manufacturer's instructions on use and the filling of its canisters. You 

will find it easy to use as long as you follow proper precautions. 

To begin stove operation, you must first fill the canisters with alcohol fuel. Inside the canister is 

a "wick-‐like" material that absorbs alcohol. Once filled, the alcohol will last three to four hours. 

If the stove is not in use for a long period of time, place the rubber seal over the burner opening 

to reduce evaporation of the alcohol. 

Safety Equipment 

You can never be prepared enough for emergencies that may arise at sea. During commissioning 

of your J/105, triple check that you have all required safety gear and adequate spares aboard. 

Make it a policy to thoroughly brief any first time crew members with emergency procedures 

including man-‐over-‐board, fire, and sinking. Please contact your local U.S. Coast Guard office for 

up to date USCG safety requirements. 

IT IS THE OWNER’S RESPONSIBILITY TO COMPLY WITH ALL FEDERAL AND STATE REGULATIONS WITH 

RESPECT TO SAFETY EQUIPMENT; OPERATION OF THEIR VESSEL; AND SAFETY OF ALL PASSENGERS 

Maintenance Tips 

Even though modern construction has helped reduce upkeep, regular attention should be given 

to the maintenance of your boat. This includes the fiberglass exterior surfaces, the interior wood 

surfaces, and the mechanical and electrical systems. 

A well-‐maintained boat will not only bring you years of enjoyment, but most importantly, will 

bring you greater personal pride and joy. 

Fiberglass/Gelcoat 

Apply a marine wax to the hull topsides at least twice annually to preserve the “factory fresh” 

appearance for many years. Be sure fiberglass surfaces are clean and free of salt before waxing. 

Abrasive cleansers should never be used for general cleaning as they can severely mar the shiny 

gelcoat finish. 

Bottom Paint 

Keeping your bottom clean is of paramount importance as it not only keeps off bottom growth, 

but maintains passage-‐making speed. Even though you have applied anti-‐fouling paint, take a 

swim once a month or so (or hire a diver) and scrub the bottom and propeller with a scrub brush 

or lightly abrasive sponge pad.


Zincs 

The shaft zinc should be inspected for integrity. If it is severely pitted, replace it immediately. 

Remember it is a sacrificial anode to protect the propeller and shaft from electrolysis. It can 

deteriorate quickly, so inspect it frequently particularly if in a known “active” harbor. The split 

design allows replacement while the boat is in the water. Unusually rapid zinc deterioration may 

be a sign of other electrical problems. Proper inspection and immediate corrective action should 

be taken to identify and isolate the source of electrical current. Failure to do so may lead to 

damage of the propeller and shaft. 

Deck Hardware/Running Rigging 

Wash deck hardware frequently with fresh water to remove accumulated salt and grime. Salt is 

VERY corrosive and a healthy wash down after each day of use will help keep things looking 

great. Regularly wash down the jib sheets, spinnaker sheets, and other lines in fresh water. 

Check for chafe and turn non-‐tapered sheets end-‐for-‐end once every year to more equally 

distribute wear. 

Check all deck blocks and also wash them with fresh water. Most ball-‐bearing blocks need only 

hot water to cleanse them. On conventional sheave/pin blocks, wash off, disassemble, clean, rub 

a light waterproof lubricant on the center pin, and then reassemble. Use only lubricants as 

recommended by hardware manufacturers. 

Furthermore, check and lubricate the sheaves and blocks on the mast. Also, ensure the 

turnbuckles are clean and well lubricated. Without proper care they can “freeze up”. 

In general, it is handy to keep a spray can of an appropriate light lubricant in your tool kit for 

frequent squirts of blocks, shackles, mainsheet travelers, and other moving fittings. 

Winches & Rope Clutches 

Read the manufacturer’s manuals on winch and rope clutch maintenance. Winches are fine 

pieces of machinery that for the most part take little effort to maintain. However, all too 

frequently, they suffer neglect because no one can see how much they wear down or get dirty. 

Clean And Lubricate Them! It takes little time to disassemble and put back together. Note that 

the gears and bearings are lubricated with special winch grease. Pawls and pawl springs need 

only a light oil. Keep spare pawls and springs in a kit for replacement. 

Deck Hatch 

Hatches need lubrication of their hinges with a silicone grease once a year. Also check the seals 

to see they are not unduly cracked, or are losing their ability to seal correctly. To increase 

traction on the plastic hatch covers, some owners prefer to apply non-‐skid tape. The foredeck 

hatch seals and hinges can see the quickest wear especially if the spinnaker is being actively 

hoisted and doused through this hatch. If you like to leave the spinnaker tack line, sheets and 

halyard rigged to the spinnaker while it is below, it is better to use the “vent” setting while 

dogging the hatch to reduce torque on the frame and reduce potential for premature problems.


Cabin Ports 

The ports are made of acrylic and are highly impact resistant. However, avoid highly abrasive 

cleansers which can scratch them. Instead, use mild soap and water to clean ports. Avoid 

chemical solvents, notably acetone, which can "melt" the ports...i.e. smear its smooth finish. 

DO NOT PERMIT ACETONE OR TEAK CLEANER TO GET ON PORTS OR HATCHES AS THEY WILL 

DISINTEGRATE AND “BLUR.” 

Stainless/Chrome 

Salt is an extremely corrosive element and whenever possible owners should spray all stainless 

and chrome deck hardware with a healthy amount of fresh water after sailing each day. 

Hardware like the pedestal guard, stanchions, handrails, bow/stern pulpits, and winches can be 

treated with Never-‐dull® or other light cleansers. After applying cleanser, polish to a gleam with 

a clean cotton rag. For more aggressive cleaning a product called Wichinox (made by French 

company Wichard) has been highly recommended for cleaning and protecting SS. 

Optional Wheel Steering System 

Your steering system is the most important system on board your boat 

As with all mechanical systems used in the harsh marine environment, proper inspection and 

maintenance is required for long life and years of proper service. Systems that have not been 

maintained and lubricated properly may show signs of wear early and perform less than 

satisfactory. Therefore, it is important that all boats fitted with wheel steering systems get an 

annual inspection of the critical system parts and that routine maintenance guidelines are 

followed. 

Jefa Rudder Bearings & Gaiter 

Bottom Bearing -‐ The bottom bearing doesn't need any maintenance except for a good hose down 

when the boat is taken out of the water. The main reason for this hose down is to remove the salt 

water out of the bearing housing so it can't crystallize. If the shaft rotates irregularly, it could be 

that some rollers have developed a flat side. 

The exchange of the rollers is quite simple: Lower the rudder out of the boat. Remove the thin 

Delrin ring holding the roller track. Now the rollers and roller track will fall out. Mount the new 

rollers. To ease this job one can apply a film of detergent (soap) to the inside of the bearing 

housing, so the rollers will stick (NEVER use any grease). Mount the bottom roller track again 

and clip-‐in the newly supplied Delrin ring. 

Top Bearing -‐ The top bearing doesn't need any maintenance. Unless the bearing is exposed (no 

deck cover present) one should yearly hose it down to wash away any sand and dust between the 

rollers and the housing. 

Gaiter -‐ Gaiters should be inspected yearly for mechanical damage. Carefully inspect the complete 

gaiter surface if any cracks are present, especially around the clamps. If you don't trust the 

sealing capabilities of the gaiter any more, replace it with a new one. Gaiters can be supplied in 

unglued state, so the rudder shaft doesn't have to be dropped. Bend the new gaiter around the


rudder shaft, apply the specially supplied neoprene glue on the indicated area. Carefully press 

the surfaces together and let it dry for a while. Mount the clamps again. 

Fiberglass/Gelcoat/Formica 

Interior gelcoat surfaces should be cleaned periodically with non-‐abrasive cleansers and smooth 

areas should be waxed. Formica should be cleaned with non-‐abrasive cleaners. 

Wood 

On unfinished teak, scrub off the gray weathered look and dirt with water and a stiff scrub brush, 

then apply one of the many available teak cleaners. 

On oiled surfaces, additional coats can be easily applied with a foam brush or sponge. For an 

even finish the oil should be rubbed with a rag shortly after application. 

On varnished surfaces, consult your dealer or a professional as to the best procedures. It takes 

great care, time, and patience to do the job correctly. 

Bilges 

Bilges are painted with air-‐dry gelcoat to prevent water permeation and accumulation of mildew. 

They should be washed regularly with strong solvents to keep them smelling clean and to 

prevent the fouling of bilge pumps.


Annual Maintenance Checklist 

Running Rigging 

___ Check running rigging lines for wear at splice, turning 

blocks, etc. 

___ Inspect blocks and shackles for wear. Clean and 

lubricate or replace as necessary. 

___ Service winches, check for free spinning operation 

(bearings) and ratchet stop action (pawls). 

Deck Hardware 

___ Check lifeline integrity, stanchions, and pulpits. 

___ Check all cleats for signs of fatigue. Tighten fasteners 

or replace as required. 

___ Re-caulk chainplates. Remove stainless cover, clean & 

re-caulk perimeter. 

Steering System 

___ Consult Edson maintenance guide (OPTIONAL WHEEL 

STEERING). 

___ Check rudder for impact damage or cracks. 

___ Check rudder shaft play in bearing tube. 

Thru Hull & Seacocks 

___ Check seacock integrity, operation, and watertightness, 

Replace, reassemble, and lubricate as required. 

___ Check hose attachment and clamps. 

Electrical 

___ Disconnect power source when making repairs or 

adjustments to electrical systems. 

___ Check battery charge, terminal connections. 

___ Check electrical panel, breakers, and switch condition 

and operation; tightness of wire connections. 

___ Check running light operation. 

___ Check ground wire attachment to keel, mast step, thru 

hulls, and engine. 

___ Check seal of electrical solenoid valve and ensure it 

closes when switched to “OFF” position. 

Engine & Drive Train System 

___ Read engine owner’s manual maintenance guide. 

___ Check engine fluid levels and systems for leaks- shut-off 

controls. 

___ Check throttle action - start and stop controls, cable 

clamps, etc. 

___ Check exhaust system soundness, hose clamps. 

___ Check coolant system, hose clamps, intake, and filters. 

___ Check transmission shift lever action, control cables, 

clamps; fluid level and alignment. 

___ Check alignment of shaft, coupling, and prop 

attachment- key, nuts, and cotter pin. Also check shaft 

zinc. 

___ Check shaft log tube integrity, packing, hoses, and 

clamps. 

___ Check strut bolt attachment, cutlass bearing, and shaft 

bolts. 

___ Check all engine wire connections. 

Fuel System 

___ Check fuel tank and gauge, hoses, clamps. 

___ Check fuel fill hoses and connections. 

___ Check fuel filters. 

Keel 

___ Check keel bolt nuts for tightness. Do not arbitrarily 

tighten bolts unless you’ve experienced a severe 

grounding. If there is concern for leakage, consult your 

dealer or professional yard. 

Plumbing 

___ Check bilge pump function, electrical wiring, hose 

clamps, and strainer. Clean, disassemble, lubricate as 

required. 

___ Check head and holding tank hoses, clamps, 

connections, and valves. 

Water System 

___ Check water tank hoses, clamps, valves, connections. 

___ Check water filters. 

Mast & Standing Rigging 

___ Inspect all mast termination fittings and halyard sheaves 

and exits. 

___ Remove tape from spreader ends and clevis pins and 

inspect and re-tape


Storage Tips 

Many of the maintenance problems surrounding boats can be pinpointed during the end-‐of-season 

haul-‐out. This is the time when a careful inspection will reveal the ravages of a long 

summer. If you live in colder climates, it is also the time to prepare the boat for what might be an 

even more brutal winter ashore. 

First, clean your boat as thoroughly as possible. Get the yard to use a high-‐powered hose to clean 

off most of the growth before it dries onto the bottom paint. You may have to use a scrub brush 

and putty knife for heavy growth, like barnacles, and for areas around the propeller and shaft and 

underneath the keel. 

Rigging 

Sails and lines should be removed at the end of each season, rinsed thoroughly in fresh water and 

stored in a warm, dry place. This will prolong their useful life as mildew can affect even today’s 

synthetic materials. Most sail lofts offer a cleaning/storage service. 

Engine 

Check the engine owner’s manual for maintenance guidance during the season and for the 

specific haul out procedures necessary to winterize the engine. Fill fuel tank to minimize 

condensation. In the exhaust system, water can accumulate in the bottom of the muffler. This 

should be drained using the drain plug, or anti-‐freeze added so residual water doesn’t freeze. 

Batteries 

It is preferable to remove the battery(ies) and store in a heated area, recharging periodically to 

maintain full charge status. If you are in warmer climates, it is possible to leave the battery 

aboard. Simply check once a month to ensure a full charge. 

Head 

Read the owner’s manual for specific maintenance procedures. Generally, you will want to drain 

all water and replace with an anti-‐freeze agent. To maintain the lubrication of its internal seals, 

flush through a light oil. Again, follow the manufacturer’s recommendations for winter 

maintenance. 

Bilges 

Pump bilges completely dry and use a strong cleaning solvent to eliminate odors and bacteria. 

Electronics 

Remove as many as possible to avoid condensation caused by the extreme rise and fall of 

temperature and humidity that come with winter.


Interior & Ventilation 

Clean the cabin thoroughly with a damp rag, for any salt left behind will breed mildew. Clean out 

the head and sinks. Any paper items-‐ books, toilet paper, and notepads-‐ should be taken off so 

they don’t mildew. 

If a winter cover is used, it is good to leave the hatches cracked open to enhance air circulation. 

This helps prevent mildew. Also, remove boat cushions and store indoors. 

Exterior 

If storing outdoors, a winter cover is recommended. It can be a simple piece of canvas forming a 

tent over the entire boat or heat-‐shrunk plastic. In either case, a tent-‐like support structure is 

necessary to prevent pools of water and to assure proper air circulation. 

Ensure the entire deck is covered to prevent uneven discoloration of the gelcoat. 

Cradle 

It is critical the boat is adequately supported. The keel must rest solidly on the main beam and 

the vertical risers should merely stabilize the boat. If it appears that the boat is supported too 

much by the vertical risers, correct the problem…. as this could structurally damage the hull. 

Mast Storage 

Store masts on well-‐padded supports and do not place any weights on them. Avoid tape on the 

mast surface as it leaves a difficult to remove residue. Wash all surfaces, sheaves, standing 

rigging with fresh water. If possible, remove all standing rigging, halyards and mast instruments 

and store indoors. For painted masts, it is usually NOT advisable to wrap the mast in plastic, as 

moisture can become trapped, and lead to premature paint blistering.


Appendix 

APPENDIX A: Best Practices – Boat Inspection 

J Boats has compiled, with the help of several industry experts, the following “best practices” 

inspection, maintenance and use guide for J/Boat owners. We urge each owner to read carefully 

the recommendations, to proactively and periodically inspect all critical components of your 

boat, and to contact anyone in the J/Boats network of dealers, builders and class associations if 

you need any assistance. 

Inspection Overview 

Considering the typical high-‐frequency use seen by many J/Boats, at a minimum, we recommend 

that owners have their boats inspected on an annual basis and that a professional survey be done 

every five years. An inspection should include a detailed review of the high-‐load areas, such as 

the rudder and keel attachments, rigging terminals, structural bulkheads, keel floors, mast step, 

mast partners, steering systems, mast and boom fittings, lifelines, etc. Inspection should also 

include identifying any possible leaks, including thru-‐hull fittings, as well as identifying worn 

rigging and hardware. Additional inspections/surveys should be performed immediately after 

any instances of grounding, collision, and/or extreme weather sailing. 

The American Bureau of Shipping (A.B.S.) calls for a detailed inspection every two years and a 

professional survey every 6 years (see Appendix B for details) following new construction. 

According to Carter Gowrie of the Gowrie Group, most insurance companies mandate a 

professional survey for boats at 10 years. A survey may indicate a structural or safety issue that 

an owner needs to address in order to continue insurance coverage. For boats that haven’t 

changed hands (which usually triggers a pre-‐sale survey), it’s otherwise left entirely to the owner 

to determine when a survey should occur. 

Keels & Keel Floors 

Overview -‐ One of the most critical areas of a modern, fin-‐keeled composite boat is the keel and 

keel floor area. This is an area that absorbs incredible loads and enormous stress. 

Use Considerations 

Groundings -‐ after any grounding or collision with any underwater object, soft or hard, be sure to 

carefully inspect the keel, sump area and keel floors for any signs of cracking or weakness. This is 

best handled by a qualified marine surveyor. Even a seemingly minor grounding can weaken the 

overall structure, particularly if left un-‐repaired for any length of time and/or if the boat 

continues to sail without repairing. There have been cases where a moderate grounding revealed 

no visible damage (due to the bottom of the boat absorbing the impact and then returning to 

shape), only later to reveal the presence of fractured glass on the inner hull laminate just aft of 

the keel. Have repairs done by a professional yard with a follow-‐up survey. 

Trailering/ Hauling/ Poppets -‐ boats that are actively trailered can be subject to excessive stress 

and strain on the keel/hull joint. In fact, years of trailering alone can subject a keel/ hull joint to 

excessively sharp vertical accelerations that can cause significant wear and tear on any portion of 

the composite structure; including keel sump and keel floors.


According to Triad Trailers, one should first load a trailer by placing most of the weight (80-‐ 

90%) on the keel as it sits in the trailer’s keel tray. Then screw each individual hull support up to 

the hull just until light contact is made. Do this for each of the six individual hull support stands 

(on the Triad Trailer). After all six stands are touching the hull release the lifting straps so the 

boat is now mostly on the keel with the hull support stands preventing the boat from tipping side 

to side. Adjust each hull support stand upwards towards the hull to a point where you are only 

able to spin the carpeted top on the hull with a good amount of force. After each hull support 

stand is properly adjusted tighten the set screw on each of the 6 hull supports. This set screw 

prevents the wing nut handle from vibrating down during travel. 

Be particularly careful when strapping a boat down to the trailer. It’s not uncommon at regatta 

venues to see boats quickly hauled and lowered onto their trailers, with little time to get the boat 

aligned and sitting properly on the poppets, then strapped down hard onto the trailer with 

powerful ratcheting webbing straps and then driven off. In short, the hull is being pulled down 

hard on top of the keel/sump and in a very short period of time is potentially subjected to 

excessive stresses and strains on the entire hull/keel/sump structure. If you have a bow-‐stop on 

the trailer, use shorter strap runs (running nearly vertical) over the boat rather than long 

diagonal straps through the bow and stern rails. This reduces the possibility of trailer flex 

contributing to any excess strain. 

Docking & Mooring -‐ care should be taken to avoid mooring or docking your boat in locations that 

can result in the keel being occasionally imbedded in the mud/sand/silt when at low tide or low 

water. A combination of the keel bulb imbedded with any sort of wave action against the hull 

can cause undue stress to the hull and structure. The same is true for boats that use special 

dockside hoisting systems to hoist the hull out of the water, while the keel remains underwater 

and unsupported. 

Maintenance Considerations 

Care should be taken to avoid having standing water in the bilge. Not only does standing water 

accelerate corrosion of wiring, fasteners and keel bolts over time, it ruins floor boards and 

interior woodwork. As the gelcoat/ paint ages in the bilge area, bilge water can eventually seep 

into the fiberglass laminate by way of pin holes in the gelcoat and weaken the fiberglass laminate 

structure. The process of hydrolysis can be initiated in the fiberglass laminate anytime there is 

ingress through cracks in the paint/gelcoat in the bilge. The process of hydrolysis is persistent 

and invisible-‐ it's water that chemically degrades the quality and strength of the laminate over 

time. Bilges (all areas under the floorboards, not just the centerline bilge) should be cleaned 

thoroughly once per year and then every five years recoated with fresh gelcoat or epoxy paint to 

ensure proper protection. In northern climates, water turns to ice in the winter. If moisture gets 

into the laminate and freezes, this can rapidly accelerate deterioration in the laminate. The New 

Hampshire Materials Testing Labs website (www.nhml.com) has an informative article on 

hydrolysis, see Newsletter of May 1, 2006. 

In any cored hull, take special care to avoid having any fasteners penetrate the inner hull 

laminate. Water in the bilge area can easily weep through the fastener into the laminate and 

cause core damage. If you need to secure a fitting or wire tie to the hull, the best fastening 

method is to glue a piece of epoxy coated marine ply to the hull and then fasten into the ply. 

A growing trend amongst active one-‐design racers is to use a dehumidifier to keep the inside of 

the boat dry. This extra step not only keeps the boat a little lighter, but helps everything from 

wiring, to woodwork, to sails, last longer.


Rigging 

Standing Rigging -‐ The general rule of thumb from Hall Spars is that standing rigging (whether 

wire or rod) should be replaced every 10 years, unless excess strain due to hard ocean sailing 

shortens this life. Fatigue can be in any form-‐ sailing in extreme wind conditions, unnecessary 

flogging of loose leeward shrouds, corrosive environment. Any signs of a broken wire strand(s) 

indicate immediate replacement is necessary. Otherwise keep a close look out for corrosion or 

cracking in the swage fittings and turnbuckle threads. In southern coastal areas, with the high 

salinity and year round warm weather, rigging must sometimes be replaced every 5 years. Fresh 

water sailed boats will generally have a longer rigging life, but are still subject to fatiguing after 

years of stress. 

Headstay -‐ The top of the headstay (wire or rod) should be checked to make sure it’s not bent. 

The fasteners and the top of the headstay foil should also be routinely checked. 

Clevis pins -‐ More rigging and spar mishaps are caused by clevis pins backing out, than perhaps 

any other culprit. If the clevis pins are semi-‐permanent (only removed a few times per year), 

then use appropriate sized cotter pin and fully bend them back around the clevis pin. Then cover 

with clear sealant rather than tape so that they are visible. 

Running rigging -‐ suffers the greatest wear and tear (chafing primarily) and should be checked 

frequently for wear, particularly high load lines like main and jib halyards and jib sheets. 

Spars 

Spar life can vary, but Hall Spar’s general rule is the mast should be replaced every 20 years. 

Frequently check your spar for problems. Spars break more often than not by a failure in the 

standing rigging, but there are some specific areas to keep an eye out for: 

Deck Area -‐ The mast section at the partners (where the mast passes through the deck) is usually 

subject to the most fatigue over time. This is due to the rig getting set up with pre-‐bend, then 

pulling on lots of backstay tension, and the constant flexing of the spar over many years. The 

best prevention is a good set of mast wedges or the Spartite mast wedge system. Unchecked 

movement at the deck can significantly shorten the life of the spar. Be especially careful about 

drilling any holes in the mast near the deck, and periodically inspect any holes in the area to 

make sure, there are no cracks developing. Any holes must be round or have rounded corners. 

Spreader Tips -‐ these should be untaped and inspected annually. Seizing wire should be redone 

annually so that the shrouds will never “pop” out of the spreader tip. Use spreader chafe covers 

that won’t collect water. 

Rig Tuning -‐ to provide not only the best performance but also a longer mast life, it’s very 

important to properly “tune the mast.” Tuning means adjusting the shroud tension so that the 

top of the mast is centered over the boat, and such that the mast is in column or straight as you 

site up the mast groove on the aft side. Proper tuning for all conditions usually means 

maintaining enough tension on the shrouds so that they do not go completely slack on the 

leeward side while sailing. Many successful one-‐design classes have tuning guides published and 

provided by sailmakers. Some of these may suggest very loose settings on the shrouds for better 

light air performance. Care should be taken by owners to avoid sailing in windy conditions with 

light air shroud settings. This may significantly shorten the life of the mast and lead to breakage.


Aluminum Spars -‐ are subject to corrosion and fittings should be routinely inspected and replaced 

when necessary. Particular problem areas over time can be fasteners around boom vang, boom 

and mast ends, and gooseneck attachment brackets. 

Booms -‐ often have a shorter life than masts, particularly on race boats that do a lot of windward-leeward 

buoy racing in breezy conditions. In some class boats it is common practice to pull the 

boom vang hard going upwind (vang-‐sheeting) and then release the boom vang several inches 

going downwind. However if one bears away without first releasing the boom vang (from its 

vang-‐sheeted position) then most booms will bend under this load. Repeated occurrences will 

shorten the life of the boom and could cause breakage. 

Rig Cutting Tool -‐ Every sailboat should carry aboard a tool that is capable of cutting through 

standing rigging quickly. When a mast does break, the portion that is in the water can easily ram 

a hole and potentially sink a boat. You may not have time to unwrap the rigging tape and pull 

clevis pins at all the attachment points. The top of the line cutters are hydraulic, which can be 

used on wire or rod rigging. For small one designs (ex…J22, J24 & J80), a good hacksaw should 

be carried at a minimum. 

Other Structure 

Bulkhead Tabbing -‐ the primary structural bulkheads of the boat are tabbed both to the hull and to 

the deck. This tabbing (or fiberglass tape) should be inspected annually and, especially, after any 

groundings or excessive exposure to “hard trailering”. If there is any evidence of gelcoat cracking 

or actual tabbing visibly loose or beginning to peel, ensure that a marine surveyor inspects the 

boat and recommends adequate remedies to correct potential damage. 

Hull-‐to-‐Deck Joint -‐ all modern J/Boats are built with a “glued” PLEXUS (2-‐part elastomer glue) 

hull to deck joint. It is an ISO/ABS approved method for hull-‐to-‐deck bonding. This joint should 

be inspected at least annually and, in particular, if any leaking is noticed inside the hull. 

Sometimes the best check is to use a “non-‐permanent dye” in water to squeeze into the hull/deck 

joint and look for “runs” inside the hull. If any leaking is observed, have the hull to deck joint 

surveyed and have the surveyor make recommendations for adequate remedies to correct 

potential damage. 

Chainplate Fittings -‐ Both port and starboard chainplates and the bow and stern chainplates 

should be checked at least annually. Look for leaks where they intersect the deck. 

Bow Sprit System -‐ the sprit system is a combination of a carbon tube, pulley system and an 

integral bulkhead/ bow support. The system can easily be damaged, particularly when struck 

laterally or vertically at the end of the pole with any force (e.g. when rounding marks hitting 

sterns, hitting metal buoys, or burying the bow in steep seas under full force of the asymmetric 

spinnaker too many times). Regularly inspect the sprit for excessive wear where the sprit 

intersects the outer bearing at full extension. 

Deck Hardware 

Lifelines & Lifeline Fittings -‐ should be replaced at least every 10 years or at the first sign of 

corrosion or damage to the wire strands, swages or turnbuckles. Many older boats have white 

vinyl coated lifelines, which are no longer allowed by ORC Offshore regulations, as the vinyl can 

disguise ongoing corrosion or damage to the wire. These should be replaced using appropriate 

wire type and diameter immediately.


Sealants -‐ used for deck hardware can last anywhere from 3 -‐10 years depending on the stress 

exerted on the hardware. If most of your hardware is still original, you should consider backing 

off the fasteners and rebedding with Sikaflex. Jib and genoa tracks are usually the first areas to 

start to leak over time. Stanchion set screws should be re-‐inspected and replaced when 

necessary. 

Additional Remarks 

There are few industry guidelines regarding pro-‐active maintenance, inspection and periodic 

replacement of key components on aging composite boats. Many owners rely on reminders from 

their boatyards for upgrades or required maintenance. For trailerable one-‐designs, it’s mostly up 

to the owner unless a surveyor gets involved with a pre-‐sale survey, and even then, not all 

surveyors are versed in composites. There are critical areas on every boat that need to be 

vigilantly looked after and routinely inspected, and we strongly encourage all owners to start by 

inspecting their boats now to best ensure a long, productive life. 

FOOTNOTE: The contents of this article are thought to be accurate, but do not necessarily 

include all of the possible preventative maintenance suggestions that owners could follow to 

ensure long-‐term, safe operation of their boats. Boats incur wear and tear in unique ways. When 

in doubt please consult a professional for advice/instruction on maintaining, inspecting, 

repairing and/or operating your boat.


Appendix B: ABS Recommended Survey Schedule 

American Bureau of Shipping (ABS) 1994 Guidelines for Offshore Racing Yachts 

Section 11-‐ Surveys after Construction 

Summary: 

ABS specifically recommends that a boat should be inspected every two years (the “Biennial Classification 

Survey”-‐ Section 11.2) and every six years after date of construction (the “Special Periodical Survey”-‐ 

Section 11.3). 

The 2 year surveys defined in Section 11.2 recommend the following survey to be completed: 

11.2(a)-‐ boat hauled, cleaned, dried in satisfactory condition for examination. 

11.2(b)-‐ general examination externally and internally and placed in satisfactory condition. 

11.2(c)-‐ all thru-‐hull openings and valves to be examined internally and externally. 

11.2(d)-‐ basic list of items to be examined and placed in satisfactory condition; including superstructures, 

hatches, companionways, ventilator and airpipe coamings, skylights, flush deck scuttles, all openings in 

yacht sides including freeing ports. 

11.2(e)-‐ general examination of the steering gear, operationally tested and placed in satisfactory condition. 

11.2(f)-‐ general examination of anchoring equipment and placed in satisfactory condition. 

11.2(g)-‐ general examination of mast, spars, standing rigging, running rigging and sails and placed in 

satisfactory condition. 

The 6 years surveys defined in Section 11.3 recommend a far more complete survey. In addition to all 

elements as described in 11.2-‐ Biennial survey, the following components need examination: 

11.3(c)-‐ examination of the rudder, bearings and stuffing boxes and placed in satisfactory condition. 

11.3(e)-‐ complete examination of the interior, including removal of lining, ceiling, portable tanks and 

ballast as may be required by Surveyor to satisfy the condition of all parts of the structure. 

11.3(f)-‐ all integral tanks tested to full capacity 

11.3(g)-‐ examine anchor windlass, hawse pipes, anchors and cables and placed in satisfactory condition. 

11.3(i)-‐ examine hull/keel fastenings and “hammer tested” to ascertain soundness by Surveyor. 

11.3(k)-‐ all sails, masts, spars, standing and running rigging to be unstepped, laid down on ground and 

fully examined by Surveyor and placed in satisfactory condition. 

11.3(m)1-‐ examine all framing, holds, hull laminate on the interior, tanks, bilges, drains and machinery. 

11.3(m)2-‐ if there's evidence of cracking, distortion, wetness or delamination, destructive or non-destructive 

testing and removal and repair of the defect carried out to the satisfaction of the Surveyor. 

11.3(m)3-‐ examine engine foundations and attachment to hull 

11.3(m)4-‐ examine the hull, fastenings and backing reinforcements regards hull fittings and attachments.


Appendix C: US Watercraft Limited Warranty 

The sole and exclusive warranty of the product is the US Watercraft Warranty printed on the Warranty 

Card furnished with the yacht. The reprinted information on the following pages is included for 

reference but may or may not include the latest information from US Watercraft.

J105 Owner Manual 2012.pdf - J/Owners

Create successful ePaper yourself

Delete template?

Save as template?